Linear evaporation source and deposition apparatus having the same

ABSTRACT

A linear evaporation source and a deposition apparatus having the same are disclosed. In one aspect, the linear evaporation source includes i) a crucible being open on one side thereof and configured to store a deposition material and ii) a plurality of partitions dividing an internal space of the crucible, wherein each of the partitions has at least one opening in a lower portion thereof. The source further includes i) a nozzle section located on the open side of the crucible and comprising a plurality of nozzles, ii) a heater configured to heat the crucible and iii) a housing configured to accommodate the crucible, the nozzle section, and the heater.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.15/884,236, filed Jan. 30, 2018, which is a continuation of U.S.application Ser. No. 14/484,691, filed Sep. 12, 2014, now U.S. Pat. No.10,081,867, which is a continuation of U.S. application Ser. No.12/972,327, filed Dec. 17, 2010, now U.S. Pat. No. 8,845,807, whichclaims priority under 35 U.S.C. § 119 to Korean Patent Application No.10-2009-126143, filed on Dec. 17, 2009, the disclosures of which arehereby incorporated by reference herein in their entireties.

BACKGROUND OF THE INVENTION Field of the Invention

An aspect of the described technology generally relates to a linearevaporation source and a deposition apparatus having the same.

Description of the Related Art

Flat panel displays have replaced cathode ray tube displays mainly dueto their light weight and thin profile. Typical examples of suchdisplays include liquid crystal displays (LCDs) and organic lightemitting diode displays (OLEDs). In comparison with LCDs, OLEDsgenerally have better luminance and viewing angle characteristics, andrequire no backlight, so that they can be realized as ultra thindisplays.

These OLEDs display images using a phenomenon whereby electrons andholes that are injected into an organic thin film through a cathode andan anode are recombined to form excitons. Thus, light having a specificwavelength is emitted by the release of energy resulting fromde-excitation of the excitons.

OLEDs are manufactured by a photolithography method or a depositionmethod to selectively form a cathode, an anode, and an organic thin filmon a substrate formed of glass, stainless steel, or synthetic resin. Inthe deposition method, a deposition material is evaporated orsublimated, deposited under vacuum, and selectively etched, or adeposition material is selectively deposited using a mask assemblyhaving a plurality of slits in a predetermined pattern.

Here, the photolithography method generally calls for applyingphotoresist to a predetermined region, and then performing wet- ordry-etching on the applied photoresist. In the process of removing oretching the photoresist, moisture may penetrate into the underlyingsubstrate. For materials which degrade in the presence of moisture, suchas an organic thin film, deposition is the primary method used to form athin film.

SUMMARY OF CERTAIN INVENTIVE ASPECTS

One inventive aspect is a linear evaporation source in which theinternal space of a crucible is divided by a plurality of partitions,and a quantitative deviation between deposition materials remaining inthe divided spaces of the crucible is minimized, thereby making itpossible to prevent a layer from being non-uniformly formed, and adeposition apparatus having the same.

Another aspect is a linear evaporation source which includes a cruciblebeing open on one side thereof and storing a deposition material, aplurality of partitions dividing an internal space of the crucible andeach having at least one through-hole in a lower portion thereof, anozzle section located on the open side of the crucible and having aplurality of nozzles, a means for heating the crucible, and a housingaccommodating the crucible, the nozzle section, and the heating means.

Another aspect is a deposition apparatus which includes a processchamber, a linear evaporation source located on one side of the processchamber, and a substrate holder disposed opposite the linear evaporationsource. The linear evaporation source includes a crucible being open onone side thereof, a plurality of partitions dividing an internal spaceof the crucible and each having at least one through-hole in a lowerportion thereof, a nozzle section located on the open side of thecrucible and having a plurality of nozzles, a means for heating thecrucible, and a housing accommodating the crucible, the nozzle section,and the heating means. Another aspect is a linear evaporation source formanufacturing flat panel displays comprising: a crucible being open onone side thereof and configured to store a deposition material; aplurality of partitions dividing an internal space of the crucible,wherein each of the partitions has at least one opening in a lowerportion thereof; a nozzle section located on the open side of thecrucible and comprising a plurality of nozzles; a heater configured toheat the crucible; and a housing configured to accommodate the crucible,the nozzle section, and the heater.

In the above source, the partitions are integrally formed with thecrucible. In the above source, the opening includes a slit extending ina direction where the deposition material is evaporated. In the abovesource, a stepped recess is formed in an upper portion of each of thepartitions. In the above source, the heater is located on sides of thecrucible when the crucible has the open upper side. In the above source,the deposition material includes an organic material.

Another aspect is a deposition apparatus for manufacturing flat paneldisplays comprising: a process chamber; an evaporation source locatedinside the process chamber and configured to contain and spray adeposition material onto a substrate; and a substrate holder locatedinside the process chamber and configured to hold the substrate, whereinthe substrate holder is spaced apart from the evaporation source,wherein the evaporation source includes i) a crucible being open on oneside thereof, ii) a plurality of partitions dividing an internal spaceof the crucible and each having at least one opening in a lower portionthereof, iii) a nozzle section located on the open side of the crucibleand comprising a plurality of nozzles, v) a heater configured to heatthe crucible, and v) a housing configured to accommodate the crucible,the nozzle section, and the heater.

In the above apparatus, the partitions are integrally formed with thecrucible. In the above apparatus, the opening includes a slit extendingin a direction where the deposition material is evaporated. In the aboveapparatus, a stepped recess is formed in an upper portion of each of thepartitions. In the above apparatus, when the evaporation source islocated at a lower portion of the process chamber, wherein the crucibleof the evaporation source has an open upper side, and wherein the heateris located on sides of the crucible. In the above apparatus, thedeposition material includes an organic material. The above apparatusfurther comprises a transfer unit configured to move the evaporationsource in a direction substantially perpendicular to a direction wherethe crucible is open.

The above apparatus further comprises a mask pattern interposed betweenthe evaporation source and the substrate holder. The above apparatusfurther comprising a clamping member configured to clamp the substrateplaced on the substrate holder.

Another aspect is an evaporation source for manufacturing flat paneldisplays comprising: a container configured to store a depositionmaterial; a heater configured to heat the container such that at leastpart of the deposition material is evaporated; a plurality of partitionsdividing an internal space of the container, wherein each of thepartitions has at least one opening, and wherein at least two of thepartitions are configured to communicate at least part of the evaporateddeposition material with each other via the opening; and a housingconfigured to accommodate the container and heater.

In the above source, a stepped recess is formed in each of thepartitions, and wherein the stepped recess is formed substantiallydirectly above the opening. In the above source, the partitions areconfigured to communicate the evaporated deposition material with eachother via the opening until each of the partitions includessubstantially the same amount of deposition material. In the abovesource, the openings of the partitions are substantially aligned witheach other and have substantially the same size. In the above source,the opening includes a slit extending in a direction where thedeposition material is evaporated.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view illustrating a deposition apparatus accordingto an embodiment.

FIG. 2A is a perspective view illustrating a linear evaporation sourcefor a deposition apparatus according to an embodiment.

FIG. 2B is a cross-sectional view illustrating a linear evaporationsource for a deposition apparatus according to an embodiment.

FIGS. 3A and 3B are schematic views illustrating a partition in adeposition apparatus according to an embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

A deposition apparatus used for manufacturing OLED displays is typicallyequipped with an evaporation source. The evaporation source generallyincludes i) a crucible being open on one side thereof and storing adeposition material, ii) a heater configured to heat the crucible, iv) anozzle section located on the open side of the crucible, and v) ahousing accommodating the crucible, the heater, and the nozzle section.To improve efficiency of a deposition process, a linear evaporationsource, in which the crucible extends in one direction, may be used asthe evaporation source.

The deposition apparatus having this linear evaporation source preventsthe deposition material stored in the crucible of the linear evaporationsource from leaning to one side using the plurality of partitions. Sincethe spaces divided by the partitions are spaced apart with differentdistances from a heater, heat transmitted to each space varies inquantity. Thus, the deposition materials in the spaces are evaporatedwith a predetermined quantitative deviation. This deviation leads to aquantitative deviation between the deposition materials remaining in thespaces. The subsequent quantitative deviation increases a deviationbetween quantities of the heat transmitted to the deposition materialsremaining in the spaces, so that non-uniformity of a layer formed on asubstrate increases.

Further, the above quantitative deviation can increase a temperaturedeviation between the spaces of the crucible so that the crucible isrepetitively expanded and contracted by the heater, resulting indeformation of the crucible.

Reference will now be made in detail to the disclosed embodiments,examples of which are shown in the accompanying drawings, wherein likereference numerals refer to the like elements throughout. In thedrawings, the lengths and thicknesses of layers and regions may beexaggerated for clarity.

FIG. 1 is a schematic view illustrating a deposition apparatus accordingto an embodiment.

Referring to FIG. 1, the deposition apparatus 100 according to anembodiment includes a process chamber 200, a linear evaporation source300 located on one side of the process chamber 200, and a substrateholder 500 disposed opposite the linear evaporation source 300.

The process chamber 200 is configured to provide a space for adeposition process. The process chamber 200 may include aloading/unloading gate (not shown) through which a substrate S is loadedor unloaded, and an exhaust port (not shown) connected with a vacuumpump (not shown) to control an internal pressure of the process chamber200 and exhaust a deposition material that is not deposited on thesubstrate S. Here, the process chamber 200 may further include a maskassembly, which is interposed between the linear evaporation source 300and the substrate holder 500 and has a plurality of slits such that thedeposition material is deposited on the substrate S in a predeterminedpattern.

The substrate holder 500 is configured to place the substrate S loadedinto the process chamber 200, and may include a separate clamping member(not shown) for clamping the substrate S while the deposition process isperformed.

In one embodiment, the linear evaporation source 300 is located at alower portion of the process chamber 200, that the substrate holder 500is located at an upper portion of the process chamber 200, and that thesubstrate S is clamped to the substrate holder 500 so as to besubstantially parallel to the horizontal plane. Alternatively, thelinear evaporation source 300 may be located on one side of the processchamber 200, and the substrate holder 500 is located on the other sideof the processor chamber 200 such that the substrate S clamped to thesubstrate holder 500 has an angle of about 70° to about 110° withrespect to the horizontal plane. Thereby, it is possible to prevent thesubstrate from sagging due to gravity.

The linear evaporation source 300 stores the deposition material, heatsthe deposition material to spray it onto the substrate S, and therebyforms a layer on the substrate S with the sprayed deposition material.The linear evaporation source 300 has a predetermined length in onedirection. The process chamber 200 may further include a transfer unit400, which moves the linear evaporation source 300 in a directionsubstantially perpendicular to the lengthwise direction of the linearevaporation source 300 to allow the deposition material to be easilysprayed on a front surface of the substrate S. The transfer unit 400includes a ball screw 410, a motor 430 rotating the ball screw 410, anda guide 420 controlling a moving direction of the linear evaporationsource 300.

FIG. 2A is a perspective view illustrating a linear evaporation sourcefor a deposition apparatus according to an embodiment, and FIG. 2B is across-sectional view illustrating a linear evaporation source for adeposition apparatus according to an embodiment.

Referring to FIGS. 2A and 2B, the linear evaporation source 300 includesa crucible 320 having an open upper portion and storing a depositionmaterial, a nozzle section 330 located on the open upper portion of thecrucible 320 and having a plurality of nozzles 335, a heater 340 locatedon opposite sides of the crucible 320 and heating the depositionmaterial stored in the crucible 320, and a housing 310 accommodating thecrucible 320, the nozzle section 330, and the heater 340.

In the deposition apparatus 100 according to an embodiment, it isdescribed that the linear evaporation source 300 is located at the lowerportion of the process chamber 200, and thus the upper portion of thecrucible 320 is open. Alternatively, the crucible 320 may be open to alateral or lower portion depending on the position of the linearevaporation source 300.

The heater 340 is configured to heat and evaporate the depositionmaterial stored in the crucible 320. The heater 340 may be located on aside of the crucible 320 which is opposite to the open side of thecrucible 320. In this case, it takes the deposition material some timeto be heated and evaporated by the heater 340. In one embodiment, totransmit most heat to the deposition material located adjacent to theopen side of the crucible 320 such that the deposition material can beeasily evaporated, the heater 340 is located on sides of the crucible320, particularly on opposite sides of the crucible 320 when the upperside of the crucible 320 is open as shown in FIGS. 2A and 2B. In anotherembodiment, the heater 340 is located so as to surround the sides of thecrucible 320.

The crucible 320 includes a plurality of partitions 325 for dividing aninternal space thereof such that the stored deposition material does notlean in one direction. Each partition 325 is provided with at least onethrough-hole 325 b (or at least one opening) in a lower portion thereof,so that the deposition material evaporated by the heater 340 can freelyflow through the internal spaces of the crucible 320 which are dividedby the plurality of partitions 325. In one embodiment, the hole 325 bhas a circular shape or a polygonal shape (triangular, square, pentagon,etc.). The at least one hole 325 b may include a plurality of holeshaving substantially the same size or different sizes. In oneembodiment, the partitions 325 are configured to communicate theevaporated deposition material with each other until each of thepartitions 325 includes substantially the same amount of depositionmaterial. Thereby, a quantitative deviation between the depositionmaterials remaining in the spaces is minimized or substantially removed.

Here, each partition 325 is provided with a stepped recess 325 a in anupper portion thereof, so that the deposition material evaporated by theheater 340 can migrate. Thereby, the evaporated deposition material canbe uniformly sprayed through each nozzle 335 of the nozzle section 330due to a pressure difference thereof.

FIGS. 3A and 3B are schematic views illustrating a partition in adeposition apparatus according to an embodiment. As illustrated in FIG.3A, the through-hole 325 b formed in the lower portion of each partition325 may include a hole having a predetermined area or shape. Asillustrated in FIG. 3B, the through-hole 325 b formed in the lowerportion of each partition 325 may include a slit 325 c extending in adirection where the deposition material is evaporated. Thereby, thedeposition materials evaporated in the spaces divided by the pluralityof partitions 325 are allowed to freely migrate, so that thequantitative deviation between the deposition materials remaining in thespaces divided by the plurality of partitions 325 can be furtherminimized or substantially removed.

Consequently, the deposition apparatus 100 according to an embodiment isconfigured such that at least one through-hole 325 b is formed in thelower portion of each partition 325 to divide the internal space of thecrucible 320 of the linear evaporation source 300. Thus, when thedeposition material stored in the crucible 320 is evaporated, theevaporated deposition material is allowed to freely flow through thethrough-hole 325 in the internal space of the crucible 320, so that thequantitative deviation between the deposition materials remaining in thespaces divided by the plurality of partitions 325 can be minimized orsubstantially removed.

Thus, according to at least one of the disclosed embodiments, it ispossible to form a substantially uniform layer in manufacturing a flatpanel display such as an OLED display.

The disclosed embodiments are not considered limiting, and thus manychanges and modifications may be made without departing from theprinciples and spirit of the claims.

What is claimed is:
 1. A linear evaporation source comprising: acrucible having a length in a length direction and a width in a widthdirection, the crucible comprising an internal space between at leasttwo length sides, being open on one side thereof, and configured tostore a deposition material; and a plurality of partitions dividing theinternal space of the crucible into a plurality of internal spaces,wherein each of the partitions extends between the two length sides andhas at least one opening substantially centered between the two lengthsides in a lower portion thereof and at least one stepped recess formedsubstantially above and separated from the at least one opening by aportion of the partition; wherein for each partition, a width of the atleast one stepped recess in the width direction is greater than a widthof the at least one opening in the width direction.
 2. The linearevaporation source according to claim 1, wherein each partitioncomprises a bottom surface, and the at least one opening of eachpartition is separated from the bottom surface of each partition.
 3. Thelinear evaporation source according to claim 2, wherein a first distancebetween the at least one opening of each partition and the at least onestepped recess of each partition is longer than a second distancebetween the at least one opening of each partition and the bottomsurface of each partition.
 4. The linear evaporation source according toclaim 1, wherein the at least one opening of each partition has arectangular shape.
 5. The linear evaporation source according to claim4, wherein the rectangular shape has a length in a length direction anda width in a width direction, and the length of the rectangular shape islonger than the width of the rectangular shape.
 6. The linearevaporation source according to claim 1, further comprising a nozzlesection located on the open side of the crucible and comprising aplurality of nozzles.
 7. The linear evaporation source according toclaim 6, wherein the at least one stepped recess of each partition facesthe nozzle section located on the open side of the crucible.
 8. Thelinear evaporation source according to claim 6, wherein an evaporateddeposition material is sprayed through each nozzle of the plurality ofnozzles, and each nozzle corresponds to a corresponding one of theplurality of internal spaces divided by the plurality of partitions. 9.The linear evaporation source according to claim 1, further comprising aheater configured to heat the crucible.
 10. The linear evaporationsource according to claim 9, wherein the heater is located at sides ofthe crucible when the crucible has the open side.
 11. A depositionapparatus comprising: a process chamber; an evaporation source locatedinside the process chamber and configured to contain and spray adeposition material onto a substrate; and a substrate holder locatedinside the process chamber and configured to hold the substrate, whereinthe substrate holder is spaced apart from the evaporation source, andwherein the evaporation source comprises i) a crucible having a lengthin a length direction and a width in a width direction, the cruciblecomprising an internal space between at least two length sides, beingopen on one side thereof, and configured to store the depositionmaterial, and ii) a plurality of partitions dividing the internal spaceof the crucible into a plurality of internal spaces, wherein each of thepartitions extends between the two length sides and has at least oneopening substantially centered between the two length sides in a lowerportion thereof and at least one stepped recess formed substantiallyabove and separated from the at least one opening by a portion of thepartition, wherein for each partition, a width of the at least onestepped recess in the width direction is greater than a width of the atleast one opening in the width direction.
 12. The deposition apparatusaccording to claim 11, wherein each partition comprises a bottomsurface, and the at least one opening of each partition is separatedfrom the bottom surface of each partition.
 13. The deposition apparatusaccording to claim 12, wherein a first distance between the at least oneopening of each partition and the at least one stepped recess of eachpartition is longer than a second distance between the at least oneopening of each partition and the bottom surface of each partition. 14.The deposition apparatus according to claim 11, wherein the at least oneopening of each partition has a rectangular shape.
 15. The depositionapparatus according to claim 14, wherein the rectangular shape has alength in a length direction and a width in a width direction, and thelength of the rectangular shape is longer than the width of therectangular shape.
 16. The deposition apparatus according to claim 11,wherein the evaporation source further comprises a nozzle sectionlocated at the open side of the crucible and comprising a plurality ofnozzles.
 17. The deposition apparatus according to claim 16, wherein theat least one stepped recess of each partition faces the nozzle sectionlocated at the open side of the crucible.
 18. The deposition apparatusaccording to claim 16, wherein an evaporated deposition material issprayed through each nozzle of the plurality of nozzles, and each nozzlecorresponds to a corresponding one of the plurality of internal spacesdivided by the plurality of partitions.
 19. The deposition apparatusaccording to claim 11, wherein the evaporation source further comprisesa heater configured to heat the crucible.
 20. The deposition apparatusaccording to claim 19, wherein the heater is located at sides of thecrucible when the crucible has the open side.